PRW Sportsman Steel Stud Mount Roller Tip Rocker Arms are the ideal choice for a large cross-section of engines; whether it is a mild street rebuild or the performance requirements of off-road, circle track and drag racing. The PRW 4340 chromoly steel rocker bodies feature a longer pivot slot for higher life cam-shafts and are much stronger than die cast aluminum or stamped steel, so rocker arm flex is negligible. The roller tip minimizes scrubbing (the result of the valve stem pushing hard against the valve guide), reducing friction and freeing up an additional 15 to 30 horsepower over stock rockers. Each set of these 16 rockers includes PRW RockerLocs and pivot balls.